[asterisk-users] Asterisk calls between 2 private networks

[Frank]

My apologies if this topic was already discussed in the past.

Here is my scenario:
Network A - 192.168.1.0
1 Asterisk
1 Digium phone
Router does NAT from the public IP to asterisk, and forward ports 
5060tcp/udp and 10k-20k udp

Network B - 192.168.1.0
1 Digium phone, registering to the public IP of network A


My SIP.CONF has:
nat=yes
localnet=192.168.1.0/255.255.255.0
externaddr=public_ip_of_network_a
directmedia=no



The Digium on network B can register. I can see it when I do "sip show 
peer xxx". When the phones are calling each other, the signaling is 
working. They ring. But when they pick up, there is no audio, in any way.

Has anyone ever worked on the same configuration, and had success ?
If yes, I'd love to hear your story and check your configuration.

Thanks !